Agarwal, Ashwin (2018-08). A Design Approach for On-Purpose Propylene Production with Safety and Sustainability Considerations. Master's Thesis. Thesis uri icon

abstract

  • The advent of Shale Gas and the increasing spread between the supply and demand curves for propylene present an opportunity for adopting alternative pathways to produce propylene. This study aims to investigate a sustainable process design approach to on-purpose propylene production. An FEL-1 level analysis was performed on the various technologies used to produce on-purpose propylene and it was determined that propane dehydrogenation (PDH) was the most profitable route. A hierarchical approach to sustainable process design is proposed and implemented in a case study with propane dehydrogenation (PDH) as the process under consideration. A base case design was developed and avenues for reduction in overall energy and water consumption, as well as reduction in carbon and VOC emissions, were analyzed. Process integration and intensification techniques were applied to reduce dependence on external utilities and to lower the overall capital investment. Waste heat recovery and off gas recycle were additional options used to intensify the overall energy consumption of the process. Emissions from the process were calculated from the EPA's guidelines. Economic and environmental metrics models were then developed to study the impact of the integration and intensification techniques. Up to 70% reductions in CO2 emissions were achieved as a result of this approach to sustainable design. The Sustainability Weighted Return on Investment (SWROI) metric was evaluated for all cases. In addition, an inherent safety analysis was performed of the flowsheets developed and the PRI and PSI indices were estimated to identify potentially high-risk streams. Multi-objective decision making for the optimum design was facilitated by the sustainability and safety metrics augmented with the traditional economic criteria.

publication date

  • August 2018